Studies on the tetrapeptide, Thr-Lys-Pro-Arg Tuftsin: (a) Bactericidal activity using Staphylococcus aureus, Salmonella typhimurium and Streptococcus hemolyticus. (b) Tumoridical activity using peritoneal macrophages and L 1210, 3T3, 3T12 cell lines. (c) The factors responsible for the immunogenic activity using peritoneal macrophages and T lymphocytes and T dependent antigens. (d) The stimulation of antibody formation in vitro and in vivo. Study the sequence of residues around the site tyrosine of phosphoglucomutase. Continue work on cell recognition.